1. Field of the Invention
The present invention relates to a motor and a fan.
2. Description of the Related Art
Centrifugal fans used for internal cooling have often been installed in electronic devices, such as notebook personal computers. Such a centrifugal fan is arranged to rotate an impeller with a driving force generated by a motor to produce an air current inside a case of an electronic device. Electronic components, such as a CPU, which are arranged inside the case are thereby cooled. A notebook personal computer typically includes a hard disk drive and an optical disk drive. Spindle motors arranged to rotate disks are installed in these drives.
The structures of known motors are described, for example, in JP-A 2007-166851 and JP-A 2008-005588.
In recent years, with an increasing reduction in the thickness of the notebook personal computers, there has been a strong demand for a reduction in the thickness of the centrifugal fans and the spindle motors arranged in the notebook personal computers. However, in the case where a circuit board is arranged on an upper surface of a base plate, and conducting wires drawn from coils are soldered to an upper surface of the circuit board, for example, the thickness of the base plate, the thickness of the circuit board, and the thickness of a solder are simply added up to result in a large combined axial thickness. It is therefore difficult to achieve a reduction in the axial thickness of the motor with the above structure.
In this connection, in the motor described in JP-A 2007-166851, an end portion to of a conducting wire is drawn out to a space radially outside a bracket and on a back side of a circuit board, and is soldered and connected to a land arranged on the back side of the circuit board and radially outside a cut defined in the circuit board. This structure is able to reduce the axial thickness of the motor to an extent to which the axial position of the bracket and the axial position of the solder overlap with each other.
However, in the motor described in JP-A 2007-166851, the conducting wire extending from a coil is drawn to a position radially outside an outer circumferential end portion of the bracket, and is soldered to the land. This structure results in an increased radial dimension of the motor although a reduction in the axial thickness of the motor is achieved.